Air vehicle



March 20, 1945- w. F. GERHARDT AIR VEHICLE Filed Feb. 4, 1942 3 Sheejbs-Sheet l INVENTOR WILUAM F. GERHARDT ATTORNEY March 1945- w. F. GERHARDT AIR VEHICLE Filed Feb. 4, 1942 3 Sheets-Sheet 2 INVENTOR wiL LiAM F. GERHARDT BY if $77M ATTORNEY March 20, 1945. w. F. GERHARDT AIR VEHICLE Filed Feb. 4, 1942 3 Sheets-Sheet 3 INVENTOR WILLIAM F GERHARDT B fia wm/ ATTORNEY Patented Mar. 20, 1945 UNITED STATES PATENT OFFICE r 2,371,687 i j AIR VEHICLE William Gerhardt, Detroit, Mich. Application February 4, 1942, Serial No. 429,491

4 Claims. (Cl. air-17) I This invention relates to aerial vehicles and in particular it relates to aerial vehicles of the helicopter type. More particularly the invention relates to such a vehicle having the versatile function of including a self-propelling drive on land and on the water. a

Briefly, the invention comprises an aerial vehicle of the helicoptertype in which the blades are rotated by jet propulsion, the force being obtained from ablower driven by a prime mover,

.as a gas turbine; such a unit being capable of operationin the air, on land and on water by suitable manipulation of controls conveniently located within a cockpit. i

Among the objects and advantages of myinvention are to provide an aerial vehicle of the helicopter type including aerodynamic torque means in the form of a rudder positioned in relation to the vertical lift screw propeller, to vprovide means automatically responsiveto changes in the relative wind .for swinging the rudder about a first axis, and means for manuall operating the rudder about a second axis transverse to said first axis. These and other objects and advantages will appear more fully in the following detailed description when considered in connection with the accompanying drawings, in which: I

Figure 1 isa side elevation view of an aerial vehicle embodying my invention;

Figure 2 is a front elevational view thereof;

Figure 3 is an enlarged elevational view in section taken through the central body of the vehicle, and particularly as indicated by the section lines IIL-III of Figure 4;

Figure ,4 isa plan view of a power and blower unit, partly in section, taken along lines IV-IV ofFigure2; n

Figure 5 is a plan view, partlyin section, of an air screw taken along lines V-- V of Figure 1;

Figure 6 is atransverse view, in section, of an air screw taken along lines VI-VI of Figure 5;

Figure 7 is a transverse view of a tail wheel taken along lines VIIVT[ of Figure 1; n

Figure 8 is a side elevational view, partly in section, of the tail wheel as shown in Figure 7;

Figure 9 is a transverse view, in section, taken near the hub of the air screw along lines IXIX of Figure 3;

Figure 10 is a perspective view of a rudder asvsembly';

Figure 11 is a view, partly in section, of control mechanism taken along lines XI-Ifl of Figure 3; and, v

Figure 12 is a detail view, in section, of a hub member for operating auxiliary control wings.

Referring to the drawings, and in particular to Figure 1, the aerial vehicle of my invention may be divided into several units comprising essentially a cockpit I, air screw 2, power and blower unit 3, float I and tail wheel assembly 5. The cockpit I comprises a streamline housing or cabin 6 provided with windows 1, a door 8 and enclosing a pilot's seat 9. All of the controls for operating theaerial vehicle are located within the cabin 6 readily accessible to a pilot supported by the seat 9.

:The air screw 2 is formed of two blades II and 12, it being understood that three or four blades may be provided if desired. The blades I I and [2 are retained by hubs l3 and [4, respectively, forming a partof an annular member I5 freely rotatable upon a vertical tubular member, hereinafter described.

As shown in Figures 5 and 6, each of the air screw blades II and [2 includes a. wing surface which presents astream'line contour in cross section. The air screws contain a longitudinal ex- .tending partition l6 forming a passageway ll extending from the stem of the air screw blade and extending to an opening is at the trailing end of the air screw at which point the wing section flares outwardly as shown in Figure 6. The stems of the air screws, as shown in Figure v3, extend within the hubs l3 and I4 and are retained therein by roller and thrust bearings is which allow rotational movement of the air screws about their own axes but retain the screws from outward movement. Th action of these screws or blades in rotation is much like the action of the autogyro in that they are free to follow the line of the combined reaction or centrifugal force and thrust. Thus, except for local bending the only necessity for strength is to withstand the centrifugal force.

As shown in particular in Figure 3, the blades H and I: are supported by hubs l3 and I! respectively forming a part of an annular bracket l5 freely rotatable about a vertical tubular column 24. Ball bearings 25 interposed between the annular member; l5 and,tubular column 24 facilitates. the free rotary movement of the bracket. A plate, 26 secured to the outer end of each of the hubs l3 and H, in cooperation with spacer sleeves 21 and bearings l9, retain the stem portions of the blades H and I: in relative association with the hubs l3 and I4 while permitting free rotational movement of the blades about their own axes. The blades, however, are restricted in their permissible rotation about their own axes by springs 28 (Fig; 9) operating upon an arcuate guide rod 29supported by brackets 3| attached to the retaining plate 26. A projecting arm 32 extending fromthe stem 01' the air screw blades engages with the springs 28 to maintain the blades in their normal or equilibrium position.

Near the tips of eachof the blades II and I2 is located an auxiliary aerodynamic control wing 33, as shown in Figures 5. and 6. This wing is spaced from the air screw blade by a strut 34 at theendofwhichthewingishinged andiscontrolled by a cable 35 operating against the action of a spring 36. These auxiliary control wings, as appearinFigureLaregivenadihedralwith respect to the horizontal for purposes of stability. The cable 35 connects with the outer tip of wing 33, pases through a guide eye 31, extends parallel with the air screw blades and engages with central controls hereinafter described.

The auxiliary control wings 33 are actuated from the cockpit through a stick or steering wheel 33 located in front of the pilot seat 3 which is supported from the floor of the cabin by a frustro-conical shaped extension 39 of the housing. The steering wheel 33 is keyed toa shaft 4|, the lower end of the shaft being moimted in a hearing bracket 42 which in turn is pivoted to a horizontal axle 43 (Fig. 11) extending from a bracket 44 attached to the housing extension 33.

By this arrangement the wheel 33 (Fig. 3) is "*PiVOCOd at its lower extremity so that it may be moved toward or away from the pilot's seat, or laterally of the pilots seat, such as the movements of a conventional airplane stick. This movement is utilized for actuating the aum'liary wings 33. To accomplish this a bifurcated arm 45 pivotally attached at I33 to the bearing 42 and provided with travelers 46 engages with a groove in a hub member 43 freely slidable on a spherical bushing 41 which in turn is vertically slidable on a spacer sleeve 5| positioned outside of the vertical column 24. By this connection, movement of the stick 4| in a lateral direction tilts the hub member laterally on the spherical bushing 41.

To transmit this movement from the relativelv stationary cockpit to the auxiliary wings 33, a pairofbellcrankarms52isprovided. Thesebellcrank arms are mounted on brackets 53 extendingfromthe annularmember I5. Oneendof each bellcrank arm engages a second groove in the hub 49 while the opposite end of each bellcrank arm connects with the cable 35 leading to the auxiliary wings 33.

A lever I84 forming a vertical extension of the bifurcated arm 45 provides manual means for elevating or lowering the hub member 43, thus forming an independent control for adjusting the auxiliary wings 33.

Forward movement of the vehicle is attained by moving the stick 4| in a forward direction. To obtain this function, a sprocket I35 is attached to the bracket 42, and through a chain I86 communicates with a sprocket l8'l pinned to the traveller 48 (Fig. 12). Therefore, forward movement of the stick tilts the hub member 43 in the plane of the longitudinal axis of the vehicle. This movement of the hub operates the auxiliary wings 33 to cause the fore and aft wings to incline in opposite directions, thus tilting the vertical axis of the vehicle and moving the vehicle in a forward direction.

As appearing in Fig. 3, the vertical column 24 provides the main structural element which con'-. nects the principal units of the air vehicle together. The upper end of the vertical column 24 is attached to a flange 54 secured to the extension member 39 of the housing 6. The lower end of the vertical column 24 is attached to flanges 55 and 55 secured to the float 4. Intermediate the cockpit and the float is the power imit 3 and the air screw blade supporting annular member l5, both of these units being rotatable about the versleeve 51 which extends from the float 4 to a thrust bearing 58 which supports the load of the power unit 3. A spacer washer 53 separates the power unit 3 from the annular member l5, and the vertical lift load of the air screw blades is carried by a thrust bearing GI mounted between the annular member l5 and the spacer sleeve 5|, the upper end of which bears against the flange 54 supp rt ng the cockpit.

The power unit comprises essentially a rotor frame 82 as shown particularly in Figures 3 and 4. This unit consists in general of a gas turbine in combination with a blower. The gas turbine provides the means of propelling the rotor 62 which in turn functions as a blower through which air is forced through the air screw blades and ejected at the trailing tip ends of the blade thus providing a jet propulsion for rotating the blades in a. horizontal plane. The rotor frame 62 is supported by the vertical column 24 through ball bearings 53. Located within the rotor frame 52 is a direct burning jet G4 which provides a combustion chamber 65. This chamber is preferably lined with a refractory material, such as carborundum, to withstand the high temperatures of combustion. The inner mouth of the combustion chamber is providedwith a check valve 36 which opens into an air inlet passage 31 while the outer mouth of the combustion chamber is provided with a flap valve 63. By-- pass chambers 63 are provided'on each side of the jet burner 64 and these by-passage ways converge to form a single passageway II positioned so as to extend at the outer periphery of the rotor in a position substantially tangent to the rotor. By this construction the gases are ejected from the rotor in a manner to cause rotation of the power unit. when the jet is discharged the bye ways thus provided act as a thrust augmentor to draw large quantities of air from the intake manifold which cuts down the speed of Y the jet in the passage-way II and decreases the tical column 24. The power \mit is heldin spaced function to cool the jet 64.

kinetic energy loss at any given speed of rotation of the rotor as compared with the straight jet operation. In addition the by-pass chambers 53 Also, the high velocity of the air as it flows into the intake manifold 61 by means of the inspirator action produces a velocity head of several atmospheres sufficient to obtain high efliciency of the combustion. This action supplements the pressure obtained at this point by means of the centrifugal force acting on the air column which in itself is hardly sufflcient to obtain high efliciency.

Two complete combustion units are employed in diametrically opposed positions.

Fuel for the combustion chamber 65 is drawn from a fuel tank 12 forming a part of the float 4. An aperture I3 extending through the flange 55 and through the vertical column 24 permits the fuel to enter the interior of the tubular column 24. A conduit 14 within the tubular column extends to a point near the bottom of the fuel tank through a valve I5 and ending at a well I5 formed in the rotor frame 52. A continuation conduit ll connects the well 16 with the combustion chamber 65. The well 15 forms a chamber, and packing l8 seals the chamber with the vertical column 24. As the power unit is rotated by means hereinafter described a suction is formed in the combustion chamber and in the well 16 which draws the fuel up the conduit 14 and into the well 16. From this point the fuel is carried out by suction and by centrifugal force to the combustion chamber 35.

' (Fig. 11) extending from a sleeve 84 positioned around the steering shaft H. A hand control lever 85 also extending from the sleeve 84 provides manual-means for actuating the fuel valve.

Ignition means in the form of a spark plug 88 is associated with the combustionchamber 85 for the purpose of initiating combustion. An electrical wire 81 connects the spark plug 88 with an insulated sleeve and brush contact mechanism 88 through which electrical energy may be transferred through the stationary vertical column 24 to the rotating terminal mechanism. The electrical wires leading to the brush mechanism 88 may be connected to any conventional means (not shown) for supplying electrical energy.

After the gas turbine is once set in operation continuation of the ignition system is not usually necessary.

In order to initiate rotation of the power unit conventional combustion engine starting means may be employed. For this purpose a ring gear 89 secured to the base of the rotor frame 82 meshes with a drive gear 9| driven by a motor 92 supported by the float 4. The relationship of the drive gear 9I and ring gear 89 is such that the gears become aligned only when energy is supplied to the motor 92. As soon as the power unit begins to rotate by its own force the gear 89 throwsthe drive gear 9I into a disengaging position.

Associated with the gas turbine is an aerodynamic transmission in the form ofa blower or centrifugal pump. This includes a plurality of blades 93 forming a part of the rotor frame 82. These blades together with the rotor frame form a plurality of passageways 94 which upon rotation of the power unit draws air from the lower central portion of the rotor at which point the passageways 94 are open to the atmosphere and throws the air at high velocity toward the outer periphery of the blower. Surrounding the outer periphery of the blower is an enclosure 95 which extends downwardly from the annular member I5. This enclosure functions to collect the air generated by the blower and. direct the air to the air screw blades as shown ,by the indicating ilow line arrows in Figures 3 and 4. The enclosure 95 while confining the air generated by the blower does not contact with the blower or the rotor frame 82 so that the relative rotary movement of the annular member I5 and the rotor frame 82 remain independent.

To facilitate the movement of air from the blower through the air crew blades, a shutter valve 98 is provided. This shutter valve is attached to a shaft 91 mounted in each hub member I3 and I4 in a manner so that when the shutter is in closed position air from the blower is prevented from moving through the air screw blades. This requirement is necessary in order to prevent rotation of the air screw blades when it is desired to maintain them in an inoperative position while the power unit is in operation.

The shutter valve 98 is operated from the cockpit through the actuation of a hand lever 98 (Figs. 3 and 11). The hand lever 98 is attached to a, ring or band 99 extending loosely around the base portion of the housing extension 39. A plurality of diagonally disposed slots I8I are formed in the band 99 into which a pin l82extends from a grooved ring located inside of the housing extension 39. Actuation of the hand lever 98 causes a circumferential movement of the band 99, which, through theslots III and pins I82, causes a vertical movement of the ring I83. A bell crank arm I84 pivoted to the bracket 53 has one of its arms extending into the groove of the ring I83. Th opposite end of the bell crank arm engages with a connecting link I85 which joins the shaft 91 through a connecting arm I88. By this arrangement circumferential movement of the band 99 by the hand lever .99

is converted into a vertical movement of the ring I83 which in turn operates the shutter valve 98. The grooved ring I83 provides an association with the bell crank m which permits the relative movement, as described, I to. function notwithstanding the relative movement between the cockpit and the rotating annular member I5 which supports. the shutter 98.

Means are also provided to lock the air screw in any desired position when it is not intended that it should rotate. This is accomplished by a brake ring I81 forming a part of the annular member I5. Slots I88 are provided in this brake ring to provide clearance for the auxiliary wing control cables 35. In cooperative position with the brake ring I8I is a brake plunger I89 vertically movable in a bracket III attached to the cockpit housing 8. A spring. II2 functions with the brake plunger I89 tending to engage the latter with the brake ring I81 thus locking the brake ring with the cockpit housing 8 and preventing rotation of the air screw blades. The brake plunger I89 may bewmoved out of engagement with the brake ring I8I by means of a hand lever II3 associated with a cam II4 engageable with the upper portion of the brake plunger I89.

One of the features of my invention is the provision of means for driving the vehicle while it is on the ground and on the water. A turbine drive wheel hereinafter described is utilized for this purpose. Power to drive the turbine wheel is obtained from the exhaust gases of the gas turbine power unit. A receiving manifold II8 (Fig. 3) is adaptable for alignment with the gas turbine discharge passageway II and for collecting the gases and forcing them through a flexible conduit II 8 leading to the turbine wheel. The receiving manifold I I5 is positioned by brackets II 1 joining a central hub II8 which is vertically slidable on the spacer sleeve 51. As shown in Figure 3, the receiving manifold H5 is illustrated in aligned position with thedischarge end of the gas turbine. v The receiving manifoldmay be lowered into the position Il5 A as shown by the dot and dash lines, thus being entirely in inoperative position with respect to the gas turbine. In order to elevate and lower the receiving manifold II5 a slot H9 is formed through the vertical column 24 and through the spacer sleeve 51.- Through this slot a pin I-2I engages with a rod I22. The rod in turn is attached to an arm I23 pivotally supported by the housing extension 39, and a hand lever I24 forming a continuation of the arm I23 provides manual means for controlling the elevation of the receiving manifold II8. I

The float 4 supports the vehicle on water and consists essentially. of a pontoon. or boat shell I28 which is the basis for supporting the main structure and the vertical column 24. As hereinbefore stated, a portion of the unit forming the float 4 is partitioned to function as a fuel reservoir for the gas turbine. A filler cap and fitting I26 (Fig. 3) located on top of the pontoon I serves as an inlet to the fuel tank. The pontoon I25 includes amphibian features by supporting a tail wheel I21 (Fig. 2), and a pair of sociated with a hub I supported by a bifurcated arm I36 pivoted vertically in a hub I31 forming a part of a tail member I38 (Fig. 1) extending from the aft end of the pontoon I25. The spindle I39 of the bifurcated arm I 36 (Fig. is hollow and is adapted to engage with the conduit II6 leading to the receiving manifold II5. A short length of conduit I (Fig. 8) extends from the opposite end of the spindle I39 and flaresoutwardly as it engages the air turbine I33. A shutter valve I42 is positioned within the flared out portion of the conduit I so that upon actuation of the shutter valve the direction of flow of gases as it enters the turbine may be changed to accommodate a forward or reverse rotation of.the tail wheel I21. A lever I43 operates the shutter I42 and is held in its normal forward position by means of a spring I44. Attached to the lever I43 is a cable I45 which, as shown in Figure 3, leads to a cockpit control. This cable I45 passes around a pulley I46 located within the vertical column 24. The upper end of the cable connects with an arm I41 pivotally supported by the housing extension 39, and a hand lever I48 joiningthe' arm I41 provides manual meansfor controlling the forward or reverse movement of the tail wheel I21.

As shown in Figure 'I, a conventional brake band mechanism I49 is located within the brake drum I34 and is operable by a sleeve I 5| rotatably mounted on a wheel axle I52. This sleeve I5I includes conventional cam means for operating the brake band and includes an operating lever I53. A cable I54 (Figs. 1 and 3) extends around a pair of pulleys I55 and I56 located within the verticalcolumn 24. The cable I54 extends to a lever I 51 pivotally supported by the housing 6 and operable by a foot pedal I58.

The exhaust gases from the gas turbine act upon the turbine iii to cause the vehicle to move along in either a forward or reverse direction. By the same power means, the vehicle is caused to be navigated in water. To facilitatethis function a plurality of blades or paddles I59 (Fig. 7) extend radially from the brake drum I34.

, Steering of the vehicle on either land or water is accomplished by pivotal movement of the tail wheel I21. A bevel gear I6I is keyed to the spindle I39 and. as shown in Fig. 1, meshes with a complementarybevel gear I62. A shaft I63 is keyed to the bevel gear I62 and the shaft is supported by a bearing I64 secured to the extension member I38. A mitre gear I65 (Fig. 3) is keyed to the opposite end of the horizontal shaft I63. This gear meshes wtih a complementary mitre gear I66 keyed to a vertical shaft I61 within the vertical column 24. At the upper end of the vertical shaft I61 the shaft is coupled to a short horizontal shaft I68 through a pair of mitre gears I69. The opposite end of the shaft I68 is also provided with a bevel gear I1I which meshes with an intermediate gear I12 supported by the bracket 44. Also meshing with the gear I12 is a bevel shaft 4I. By this arrangement of gears and shafts rotary movement'of the steering wheel 38 imparts steering movement to the tail wheel I21.

In order to prevent a tendency of the cockpit to rotate with the power plant due to the friction of the bearings, a torque controlis provided. This consists essenfially of a rudder I14 (Fig. 10) positioned by-a bracket member I15 which-extends rearwardly from the tail wheel supporting hub I31 .(Fig. l). The rudder I14 is pivotally connected to a bracket I16 and the bracket in turn is pivotally connected. but in a transverse direction relative thereto, to a yoke I 11 forming the end of the bracket member I15. An axle I18 forming the pivot for the yoke I11 and the bracket I16 serves at its outer ends for guides through which a pair of cables I19 extend. These cables are attached at one end to a pair of arms I8I (Fig. 7) attached to the spindles I39. Thus the control of the rudder I14 is actuated at the same time and by the same means as is utilized to control the movement of the tail wheel I21. The opposite end of the cables I19 are attached to the leading edges to a pair of wingfoils I82 extending transversely and centrally of the rudder I14. This pair of wing foils function with the double pivoted connection associated with the rudder I14 to maintain the. rudder in a headed position relative to the resultant slip stream produced by the vehicle in flight.

In the operation of the vehicle, the pilot starts the motor by engaging the 'gnition system and by conventional controls (not shown) causing the starting motor 92 to rotate. This action provides a suflicient amount of suction to draw fuel from the fuel tank into the well 16 from which it enters the combustion chamber 65. Combustion of the gases is started by means of the spark plug 86. After the chamber has been sufliciently warmed by this burning the ignition system may be disengaged. Thereafter the gasoline throttle 85 may be adjusted to provide the desired motor speed. During the neutral operation of the motor the receiving manifold II5 (Fig. 3) is also in its neutral position as shown by the position II5A.

While the air vehicle is resting upon the ground the shutter valves 96 are in their closed position so as to prevent the air forced from the blower tion of' the vehicl the brake plunger I09 is engaged with the brake ring I81.

To take off from the ground the pilot actuates the brake lever I I 3'soas to raise the brake plunger I69 from the brake ring I91 and opens the shutter valves 96 to the position as shown in Figure 3. Operation of the shutter valves is controlled by operation of the hand lever 96 located near the floor of the cockpit. The air screw now begins to revolve by jet propulsion.

By meansof the auxiliary wings 33 located near the ends of the air screw blades and operated by movement of the stick H or lever I84, the pilot keeps the angle of incidence of the blades very low in order that the screw reaches take of speed quickly. By movement of the lever I84 in a forgear I13 keyed to the lower end of the steering is ward direction the vehicle may be made to leave the ground. The longitudinal movement of the lever I84 varies the position of the auxiliary wings and by this control the pitch of the blades may be varied to obtain the desired rate of climb. It will usually be found that one blade will lift higher than the other and produce an uabalance as it is not possible to position the blades exactly alike. In this case, before the vehicle lifts off the ground, the pilot adjusts the stick laterally so as to tilt the grooved hub member 49, thus obtaining a variance in the position of the auxiliary wings 33 on the different blades until the blades lift equally. When satisfactory balance is accomplished the pitch is further increased and the vehicle ascends.

To pitch or bank or rotate about any horizontal axis of the vehicle the pilot simply moves the stick II in the direction he wishes the vehicle in a tilting or direct vertical movement of the grooved hub 49. When the hub is tilted a corresponding motion is transmitted to the auxiliary wings. As one of the auxiliary wings is actuated the reverse action takes place respecting the auxiliary wing on the opposite blade. As the bladesare free to rotate within limits about their own axis the angle of incidence is decreased on the side toward which the stick is moved and increased on the other. Thus, a differential thrust movement is produced which tilts the vehicle producing a thrust component and the vehicle side-slips in the direction desired.

As soon as horizontal motion is obtained another change in thrust distribution results from the horizontal motion. On one side a blade is advancing forward with its peripheral speed so as to increase its eiiective speed in relation to the wind; on the other side it is retreating so as to decrease the relative speed. On account of the properties of constant incidence of the system, the angle of attack will remain in constant on the side quadrants; hence the total thrust would be greater on the side of the advancing blade than of the retreating blade, and amoment tending to bank the vehicle will be introduced. This may be counterbalanced by controlling the angle of attack by moving the stick forward and laterally to cause a decrease of angle of attack on the advancing blade and an increase on the retreating blade.

To turn the vehicle the pilot merely moves the stick to the side he wishes to turn thereby securingabannthenpullsbackonthesticktosecure the reaction to the centrifugal force. Simultaneously the stick is moved to give the turning to the central nacelle. In essence this similar to the conventional airplane turn except that more right stick is carried to take care of the diiierential thrust distribution due to forward speed.

The rudder I'll functions as a torque means to prevent the cockpit and chassis from rotating with the motor due to the friction of the bearings. Inorder totake careof alldirectionsoftheslip stream through 180 degrees the whole rudder assembly is free to pivot about its hinged support soastoheadintotheresultantstreambythe auxiliary lateral wings I82. Manual movement of the rudder is obtained by rotary movement at the steering wheel 3!.

For landin the pilot has two options. If the power plant is working then the pilot simply throttles the motor and comes down slowly to the ground. If the motor is not working the pilot allows the machine to slide down at its minimumrateofdescentonnearlngthe l ski-v groundthepiiotmovesthesticktoincreosethe.

pitch of the screw blades to obtain maximum lift.

Tooperstethevehicleonlandthepilotcloses theshuttervalvesflandengsgesthebrakc plunger I09 so that the screw blades will remain inactive. Thereafter, the hand lever I24 is actuated which elevates the receiving manifold H5 into aligned position with the discharge end of the combustion chambers. The resulting force assisted by the blowerlike by-pass adjacent to the combustion chamber produces a pressure which moves through the conduit lie, and, as shown in Figure 8, engages the wheelturbine I33 to cause the wheel to rotate. Steering is accomplished by the hand wheel 38 which en'- gages the tail wheel I21 by a direct gear drive.

in reverse the vehicle the valve I42 wig. 8) 1S actuated by the cockpit control I48 to change the direction of flow of air against the wheel turbine.

For operating the vehicle in water the same functional operations are produced, facilitated by paddle blades I59 forming a part of the tail wheel assembly.

Wnen operating as a land vehicle the foot brake pedal I58 in the cockpit serves in a conventional manner to brake the tail wheel.

From the foregoing it is believed apparent that i have provided a novel combination of elements functionally interrelated to produce a safe vehicle of practical use in the air, on land and on the water, and while I have shown and described a preferred embodiment of my invention it is to be understood that it is susceptible of those modifications which appear within the spirit of the invention and the scope of the appended claims. I

Having thus described my invention what I claim and desire to protect by Letters Patent is:

1. In a helicopter, the combination with a body, landing chassis and vertical lift screw propeller, of aerodynamic torque means, said means comprising a rudder, means for manually operating the rudder, and automatic means for maintaining the leading edge of the rudder substantially normal to. the direction of the relative wind.

2. In a helicopter, the combination with a body, landing chassis and vertical lift screw propeller, of aerodynamic torque means positioned within the slip stream of the vertical screw propeller, said means comprising a rudder, means for manually operating the rudder, and automatic means for the leading edge of the rudder substantially normal to the direction of the relative wind.

3. In a helicopter, the combination with a body, landing chassis and vertical lift screw propeller, of aerodynamic torque means positioned within the slip stream of the vertical screw propeller, said means comprising a rudder pivotedtothechassistopermitchangeofpcsiden of the leading edge of the rudder with change of the relative wind, and auxiliary Win88 extending laterally from the rudder for maintainingtbeleadingedgeof theruddersubstantially normal to the direction of the relative wind.

4. In a helicopter, the combination with a body, landing chassis and vertical lift screw propeller, of c torque means, said means comprising a rudder, a universal pivot connecting the rudder with the chassis, aerodynamic means automatically responsive to changes in the relative wind for swinsinc the rudder about a first axis, and means for menu ally operating the rudder about a second axis transverse to saidiirst axis.

-' WILLIAM 1'. GIRHARDI. 

